Betula occidentalis Hook.
water birch (black birch; mountain birch; red birch)
Betulaceae (Birch family)

Introduction to Vascular Plants


© Jamie Fenneman     (Photo ID #3450)


E-Flora BC Static Map

Distribution of Betula occidentalis
Click here to view the full interactive map and legend

Species Information

Deciduous small tree or large shrub, 3-10 m tall; bark dark reddish-brown to black.
Alternate, deciduous, rounded to sharp-pointed at the tip, usually doubly saw-toothed, thin and membranous, 1-7 cm long, leaf stalks more than 1 cm long.
Male and female flowers in separate catkins 2-4 cm long; flowers emerging before or with the leaves; catkins breaking up at maturity.
Nutlets with broad wings, at least twice as wide as the nutlets; bracts with pointed, lateral lobes.

SourceThe Illustrated Flora of British Columbia


If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.

USDA Species Characteristics

Flower Colour:
Blooming Period:
Mid Spring
Fruit/Seed characteristics:
Colour: Brown
Present over the Spring
Source:  The USDA


Ecological Framework for Betula occidentalis

The table below shows the species-specific information calculated from
original data (BEC database) provided by the BC Ministry of Forests and Range.
(Updated August, 2013)

Site Information
Value / Class




Elevation (metres)
846 75 1645
Slope Gradient (%)
12 0 150

Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]

102 10 344
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
5 0 8
Modal Nutrient Regime
# of field plots
 species was recorded in:
Modal BEC Zone Class

All BEC Zones (# of stations/zone) species was recorded in

BG(23), BWBS(9), CWH(1), ESSF(4), ICH(12), IDF(81), MS(18), PP(39), SBS(4), SWB(6)

Habitat and Range

Wet to moist streambanks, forests and marshes in the steppe and montane zones; frequent in S BC east of the Coast-Cascade Mountains, rare northward; N to AK, YT and NT, E to NF, and S to CO, UT and CA.

SourceThe Illustrated Flora of British Columbia


Synonyms and Alternate Names:
Betula beeniana A. Nels.
Betula fontinalis Sarg.
Betula occidentalis var. inopina (Jepson) C.L. Hitchc.
Betula papyrifera subsp. occidentalis (Hook.) Hult╬śn
Betula papyrifera var. occidentalis (Hook.) Sarg.

Taxonomic Notes

Cut-leaf Water Birch

Water birch is a small, shrubby birch found [particularly] in the southern interior of British Columbia and is distinguished from paper birch by its smaller size and by the presence of wartlike glands on its twigs. The leaves are roughly heart shaped with small teeth along the margins. In the cut-leaf mutant, found near Revelstoke, the developmet of the leaf is limited to narrow regions along some of the main veins so that the leaves look like mere skelteons of normal leaves.


Extracted from Griffiths and Ganders, 1983. Wildflower Genetics: A Field Guide for British Columbia and the Pacific Northwest.


Griffiths, Anthony J. F. and Fred R. Ganders. 1983. Wildflower Genetics: A Field Guide for British Columbia and the Pacific Northwest. Flight Press, Vancouver.